MT observable collections

(UI sync fix)

NLog.config

@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8" ?>
 <nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-
   <variable name="logStamp" value="${time} ${pad:padding=-8:inner=[${level:uppercase=true}]}" />
   <variable name="logContent" value="${message:withException=true}"/>
 

Torch.Server/ViewModels/ConfigDedicatedViewModel.cs

@@ -6,6 +6,7 @@ using System.Text;
 using System.Threading.Tasks;
 using NLog;
 using Sandbox.Engine.Utils;
+using Torch.Collections;
 using VRage.Game;
 using VRage.Game.ModAPI;
 
@@ -58,7 +59,7 @@ namespace Torch.Server.ViewModels
         private SessionSettingsViewModel _sessionSettings;
         public SessionSettingsViewModel SessionSettings { get => _sessionSettings; set { _sessionSettings = value; OnPropertyChanged(); } }
 
-        public ObservableList<string> WorldPaths { get; } = new ObservableList<string>();
+        public MtObservableList<string> WorldPaths { get; } = new MtObservableList<string>();
         private string _administrators;
         public string Administrators { get => _administrators; set { _administrators = value; OnPropertyChanged(); } }
         private string _banned;

Torch.Server/ViewModels/Entities/Blocks/BlockViewModel.cs

@@ -8,6 +8,7 @@ using System.Threading.Tasks;
 using Sandbox.Game.Entities.Cube;
 using Sandbox.ModAPI;
 using Sandbox.ModAPI.Interfaces;
+using Torch.Collections;
 using Torch.Server.ViewModels.Entities;
 
 namespace Torch.Server.ViewModels.Blocks
@@ -15,7 +16,7 @@ namespace Torch.Server.ViewModels.Blocks
     public class BlockViewModel : EntityViewModel
     {
         public IMyTerminalBlock Block { get; }
-        public ObservableList<PropertyViewModel> Properties { get; } = new ObservableList<PropertyViewModel>();
+        public MtObservableList<PropertyViewModel> Properties { get; } = new MtObservableList<PropertyViewModel>();
 
         public string FullName => $"{Block.CubeGrid.CustomName} - {Block.CustomName}";
 

Torch.Server/ViewModels/Entities/GridViewModel.cs

@@ -2,6 +2,7 @@
 using System.Linq;
 using Sandbox.Game.Entities;
 using Sandbox.ModAPI;
+using Torch.Collections;
 using Torch.Server.ViewModels.Blocks;
 
 namespace Torch.Server.ViewModels.Entities
@@ -9,7 +10,7 @@ namespace Torch.Server.ViewModels.Entities
     public class GridViewModel : EntityViewModel, ILazyLoad
     {
         private MyCubeGrid Grid => (MyCubeGrid)Entity;
-        public ObservableList<BlockViewModel> Blocks { get; } = new ObservableList<BlockViewModel>();
+        public MtObservableList<BlockViewModel> Blocks { get; } = new MtObservableList<BlockViewModel>();
 
         /// <inheritdoc />
         public string DescriptiveName { get; }
@@ -34,7 +35,7 @@ namespace Torch.Server.ViewModels.Entities
         {
             var block = obj.FatBlock as IMyTerminalBlock;
             if (block != null)
-                Blocks.Insert(new BlockViewModel(block, Tree), b => b.Name);
+                Blocks.Add(new BlockViewModel(block, Tree));
 
             OnPropertyChanged(nameof(Name));
         }

Torch.Server/ViewModels/Entities/VoxelMapViewModel.cs

@@ -4,6 +4,7 @@ using Sandbox.Game.Entities;
 using VRage.Game.Entity;
 using VRage.Game.ModAPI;
 using System.Threading.Tasks;
+using Torch.Collections;
 
 namespace Torch.Server.ViewModels.Entities
 {
@@ -15,7 +16,7 @@ namespace Torch.Server.ViewModels.Entities
 
         public override bool CanStop => false;
 
-        public ObservableList<GridViewModel> AttachedGrids { get; } = new ObservableList<GridViewModel>();
+        public MtObservableList<GridViewModel> AttachedGrids { get; } = new MtObservableList<GridViewModel>();
 
         public async Task UpdateAttachedGrids()
         {

Torch.Server/ViewModels/EntityTreeViewModel.cs

@@ -11,16 +11,17 @@ using VRage.Game.ModAPI;
 using VRage.ModAPI;
 using System.Windows.Threading;
 using NLog;
+using Torch.Collections;
 
 namespace Torch.Server.ViewModels
 {
     public class EntityTreeViewModel : ViewModel
     {
         //TODO: these should be sorted sets for speed
-        public ObservableList<GridViewModel> Grids { get; set; } = new ObservableList<GridViewModel>();
-        public ObservableList<CharacterViewModel> Characters { get; set; } = new ObservableList<CharacterViewModel>();
-        public ObservableList<EntityViewModel> FloatingObjects { get; set; } = new ObservableList<EntityViewModel>();
-        public ObservableList<VoxelMapViewModel> VoxelMaps { get; set; } = new ObservableList<VoxelMapViewModel>();
+        public MtObservableList<GridViewModel> Grids { get; set; } = new MtObservableList<GridViewModel>();
+        public MtObservableList<CharacterViewModel> Characters { get; set; } = new MtObservableList<CharacterViewModel>();
+        public MtObservableList<EntityViewModel> FloatingObjects { get; set; } = new MtObservableList<EntityViewModel>();
+        public MtObservableList<VoxelMapViewModel> VoxelMaps { get; set; } = new MtObservableList<VoxelMapViewModel>();
         public Dispatcher ControlDispatcher => _control.Dispatcher;
 
         private EntityViewModel _currentEntity;
@@ -29,7 +30,7 @@ namespace Torch.Server.ViewModels
         public EntityViewModel CurrentEntity
         {
             get => _currentEntity;
-            set { _currentEntity = value; OnPropertyChanged(); }
+            set { _currentEntity = value; OnPropertyChanged(nameof(CurrentEntity)); }
         }
 
         public EntityTreeViewModel(UserControl control)
@@ -67,16 +68,16 @@ namespace Torch.Server.ViewModels
             switch (obj)
             {
                 case MyCubeGrid grid:
-                    Grids.Insert(new GridViewModel(grid, this), g => g.Name);
+                    Grids.Add(new GridViewModel(grid, this));
                     break;
                 case MyCharacter character:
-                    Characters.Insert(new CharacterViewModel(character, this), c => c.Name);
+                    Characters.Add(new CharacterViewModel(character, this));
                     break;
                 case MyFloatingObject floating:
-                    FloatingObjects.Insert(new FloatingObjectViewModel(floating, this), f => f.Name);
+                    FloatingObjects.Add(new FloatingObjectViewModel(floating, this));
                     break;
                 case MyVoxelBase voxel:
-                    VoxelMaps.Insert(new VoxelMapViewModel(voxel, this), v => v.Name);
+                    VoxelMaps.Add(new VoxelMapViewModel(voxel, this));
                     break;
             }
         }

Torch.Server/ViewModels/PluginManagerViewModel.cs

@@ -6,18 +6,19 @@ using System.Threading.Tasks;
 using Torch.API;
 using Torch.API.Managers;
 using Torch.API.Plugins;
+using Torch.Collections;
 
 namespace Torch.Server.ViewModels
 {
     public class PluginManagerViewModel : ViewModel
     {
-        public ObservableList<PluginViewModel> Plugins { get; } = new ObservableList<PluginViewModel>();
+        public MtObservableList<PluginViewModel> Plugins { get; } = new MtObservableList<PluginViewModel>();
 
         private PluginViewModel _selectedPlugin;
         public PluginViewModel SelectedPlugin
         {
             get => _selectedPlugin;
-            set { _selectedPlugin = value; OnPropertyChanged(); }
+            set { _selectedPlugin = value; OnPropertyChanged(nameof(SelectedPlugin)); }
         }
 
         public PluginManagerViewModel() { }

Torch.Server/ViewModels/SessionSettingsViewModel.cs

@@ -5,6 +5,7 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using SharpDX.Toolkit.Collections;
+using Torch.Collections;
 using VRage.Game;
 using VRage.Library.Utils;
 
@@ -35,7 +36,7 @@ namespace Torch.Server.ViewModels
                 BlockLimits.Add(new BlockLimitViewModel(this, limit.Key, limit.Value));
         }
 
-        public ObservableList<BlockLimitViewModel> BlockLimits { get; } = new ObservableList<BlockLimitViewModel>();
+        public MtObservableList<BlockLimitViewModel> BlockLimits { get; } = new MtObservableList<BlockLimitViewModel>();
 
         #region Multipliers
 

Torch/Collections/MTObservableCollection.cs

@@ -1,77 +1,358 @@
 using System;
+using System.Collections;
 using System.Collections.Generic;
-using System.Collections.ObjectModel;
 using System.Collections.Specialized;
+using System.ComponentModel;
+using System.Diagnostics;
 using System.Linq;
+using System.Reflection;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Windows.Threading;
+using Torch.Utils;
 
-namespace Torch
+namespace Torch.Collections
 {
-    [Obsolete("Use ObservableList<T>.")]
-    public class MTObservableCollection<T> : ObservableCollection<T>
+    /// <summary>
+    /// Multithread safe, observable collection
+    /// </summary>
+    /// <typeparam name="TC">Collection type</typeparam>
+    /// <typeparam name="TV">Value type</typeparam>
+    public abstract class MtObservableCollection<TC, TV> : INotifyPropertyChanged, INotifyCollectionChanged, IEnumerable<TV> where TC : class, ICollection<TV>
     {
-        public override event NotifyCollectionChangedEventHandler CollectionChanged;
+        protected readonly ReaderWriterLockSlim Lock;
+        protected readonly TC Backing;
+        private int _version;
+        private readonly ThreadLocal<ThreadView> _threadViews;
 
-        protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
+        protected MtObservableCollection(TC backing)
         {
-            NotifyCollectionChangedEventHandler collectionChanged = CollectionChanged;
-            if (collectionChanged != null)
-                foreach (var del in collectionChanged.GetInvocationList())
-                {
-                    var nh = (NotifyCollectionChangedEventHandler)del;
-                    var dispObj = nh.Target as DispatcherObject;
+            Backing = backing;
+            // recursion so the events can read snapshots.
+            Lock = new ReaderWriterLockSlim(LockRecursionPolicy.SupportsRecursion);
+            _version = 0;
+            _threadViews = new ThreadLocal<ThreadView>(() => new ThreadView(this));
+        }
 
-                    var dispatcher = dispObj?.Dispatcher;
-                    if (dispatcher != null && !dispatcher.CheckAccess())
-                    {
-                        dispatcher.BeginInvoke(
-                            (Action)(() => nh.Invoke(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset))),
-                            DispatcherPriority.DataBind);
-                        continue;
-                    }
+        /// <summary>
+        /// Takes a snapshot of this collection.  Note: This call is only done when a read lock is acquired.
+        /// </summary>
+        /// <param name="old">Collection to clear and reuse, or null if none</param>
+        /// <returns>The snapshot</returns>
+        protected abstract TC Snapshot(TC old);
 
-                    nh.Invoke(this, e);
+        /// <summary>
+        /// Marks all snapshots taken of this collection as dirty.
+        /// </summary>
+        protected void MarkSnapshotsDirty()
+        {
+            _version++;
+        }
+
+        #region ICollection
+        /// <inheritdoc/>
+        public void Add(TV item)
+        {
+            using(Lock.WriteUsing())
+            {
+                Backing.Add(item);
+                MarkSnapshotsDirty();
+                OnPropertyChanged(nameof(Count));
+                OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item, Backing.Count - 1));
+            }
+        }
+
+        /// <inheritdoc/>
+        public void Clear()
+        {
+            using(Lock.WriteUsing())
+            {
+                Backing.Clear();
+                MarkSnapshotsDirty();
+                OnPropertyChanged(nameof(Count));
+                OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
+            }
+        }
+
+        /// <inheritdoc/>
+        public bool Contains(TV item)
+        {
+            using (Lock.ReadUsing())
+                return Backing.Contains(item);
+        }
+
+        /// <inheritdoc/>
+        public void CopyTo(TV[] array, int arrayIndex)
+        {
+            using (Lock.ReadUsing())
+                Backing.CopyTo(array, arrayIndex);
+        }
+
+        /// <inheritdoc/>
+        public bool Remove(TV item)
+        {
+            using(Lock.UpgradableReadUsing()) {
+                int? oldIndex = (Backing as IList<TV>)?.IndexOf(item);
+                if (oldIndex == -1)
+                    return false;
+                using(Lock.WriteUsing()) {
+                    if (!Backing.Remove(item))
+                        return false;
+                    MarkSnapshotsDirty();
+
+                    OnPropertyChanged(nameof(Count));
+                    OnCollectionChanged(oldIndex != null
+                        ? new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, item, oldIndex)
+                        : new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, item));
+                    return true;
                 }
-        }
-
-        public void Insert<TKey>(T item, Func<T, TKey> selector, IComparer<TKey> comparer)
-        {
-            var key = selector(item);
-            for (var i = 0; i < Count; i++)
-            {
-                var key2 = selector(Items[i]);
-                if (comparer.Compare(key, key2) < 1)
-                    continue;
-
-                Insert(i + 1, item);
-                return;
-            }
-
-            Add(item);
-        }
-
-        public void Sort<TKey>(Func<T, TKey> selector, IComparer<TKey> comparer = null)
-        {
-            List<T> sortedItems;
-            if (comparer != null)
-                sortedItems = Items.OrderBy(selector, comparer).ToList();
-            else
-                sortedItems = Items.OrderBy(selector).ToList();
-
-            Items.Clear();
-            foreach (var item in sortedItems)
-                Add(item);
-        }
-
-        public void RemoveWhere(Func<T, bool> condition)
-        {
-            for (var i = Items.Count - 1; i > 0; i--)
-            {
-                if (condition(Items[i]))
-                    RemoveAt(i);
             }
         }
+
+        /// <inheritdoc/>
+        public int Count
+        {
+            get
+            {
+                using (Lock.ReadUsing())
+                    return Backing.Count;
+            }
+        }
+
+        /// <inheritdoc/>
+        public bool IsReadOnly => Backing.IsReadOnly;
+        #endregion
+
+        #region Event Wrappers
+        protected void OnPropertyChanged(string propName)
+        {
+            NotifyEvent(this, new PropertyChangedEventArgs(propName));
+        }
+
+        protected void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
+        {
+            NotifyEvent(this, e);
+        }
+
+        protected void NotifyEvent(object sender, PropertyChangedEventArgs args)
+        {
+            _propertyChangedEvent.Raise(sender, args);
+        }
+
+        protected void NotifyEvent(object sender, NotifyCollectionChangedEventArgs args)
+        {
+            _collectionChangedEvent.Raise(sender, args);
+        }
+
+        private readonly DispatcherEvent<PropertyChangedEventArgs, PropertyChangedEventHandler> _propertyChangedEvent =
+            new DispatcherEvent<PropertyChangedEventArgs, PropertyChangedEventHandler>();
+        /// <inheritdoc/>
+        public event PropertyChangedEventHandler PropertyChanged
+        {
+            add => _propertyChangedEvent.Add(value);
+            remove => _propertyChangedEvent.Remove(value);
+        }
+
+        private readonly DispatcherEvent<NotifyCollectionChangedEventArgs, NotifyCollectionChangedEventHandler> _collectionChangedEvent =
+            new DispatcherEvent<NotifyCollectionChangedEventArgs, NotifyCollectionChangedEventHandler>();
+        /// <inheritdoc/>
+        public event NotifyCollectionChangedEventHandler CollectionChanged
+        {
+            add => _collectionChangedEvent.Add(value);
+            remove => _collectionChangedEvent.Remove(value);
+        }
+        /// <summary>
+        /// Event that invokes handlers registered by dispatchers on dispatchers.
+        /// </summary>
+        /// <typeparam name="TEvtArgs">Event argument type</typeparam>
+        /// <typeparam name="TEvtHandle">Event handler delegate type</typeparam>
+        private sealed class DispatcherEvent<TEvtArgs, TEvtHandle> where TEvtArgs : EventArgs
+        {
+            private delegate void DelInvokeHandler(TEvtHandle handler, object sender, TEvtArgs args);
+
+            private static readonly DelInvokeHandler _invokeDirectly;
+            static DispatcherEvent()
+            {
+                MethodInfo invoke = typeof(TEvtHandle).GetMethod("Invoke", BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly);
+                Debug.Assert(invoke != null, "No invoke method on handler type");
+                _invokeDirectly = (DelInvokeHandler)Delegate.CreateDelegate(typeof(DelInvokeHandler), invoke);
+            }
+
+            private static Dispatcher CurrentDispatcher => Dispatcher.FromThread(Thread.CurrentThread);
+
+
+            private event EventHandler<TEvtArgs> _event;
+
+            internal void Raise(object sender, TEvtArgs args)
+            {
+                _event?.Invoke(sender, args);
+            }
+
+            internal void Add(TEvtHandle evt)
+            {
+                if (evt == null)
+                    return;
+                _event += new DispatcherDelegate(evt).Invoke;
+            }
+
+            internal void Remove(TEvtHandle evt)
+            {
+                if (_event == null || evt == null)
+                    return;
+                Delegate[] invokeList = _event.GetInvocationList();
+                for (int i = invokeList.Length - 1; i >= 0; i--)
+                {
+                    var wrapper = (DispatcherDelegate)invokeList[i].Target;
+                    Debug.Assert(wrapper._dispatcher == CurrentDispatcher, "Adding and removing should be done from the same dispatcher");
+                    if (wrapper._delegate.Equals(evt))
+                    {
+                        _event -= wrapper.Invoke;
+                        return;
+                    }
+                }
+            }
+
+            private struct DispatcherDelegate
+            {
+                internal readonly Dispatcher _dispatcher;
+                internal readonly TEvtHandle _delegate;
+
+                internal DispatcherDelegate(TEvtHandle del)
+                {
+                    _dispatcher = CurrentDispatcher;
+                    _delegate = del;
+                }
+
+                public void Invoke(object sender, TEvtArgs args)
+                {
+                    if (_dispatcher == null || _dispatcher == CurrentDispatcher)
+                        _invokeDirectly(_delegate, sender, args);
+                    else
+                        // (Delegate) (object) == dual cast so that the compiler likes it
+                        _dispatcher.BeginInvoke((Delegate)(object)_delegate, DispatcherPriority.DataBind, sender, args);
+                }
+            }
+        }
+
+        #endregion
+
+        #region Enumeration
+        /// <summary>
+        /// Manages a snapshot to a collection and dispatches enumerators from that snapshot.
+        /// </summary>
+        private sealed class ThreadView
+        {
+            private readonly MtObservableCollection<TC, TV> _owner;
+            private readonly WeakReference<TC> _snapshot;
+            /// <summary>
+            /// The <see cref="MtObservableCollection{TC,TV}._version"/> of the <see cref="_snapshot"/>
+            /// </summary>
+            private int _snapshotVersion;
+            /// <summary>
+            /// Number of strong references to the value pointed to be <see cref="_snapshot"/>
+            /// </summary>
+            private int _snapshotRefCount;
+
+            internal ThreadView(MtObservableCollection<TC, TV> owner)
+            {
+                _owner = owner;
+                _snapshot = new WeakReference<TC>(null);
+                _snapshotVersion = 0;
+                _snapshotRefCount = 0;
+            }
+
+            private TC GetSnapshot()
+            {
+                // reading the version number + snapshots
+                using (_owner.Lock.ReadUsing())
+                {
+                    if (!_snapshot.TryGetTarget(out TC currentSnapshot) || _snapshotVersion != _owner._version)
+                    {
+                        // Update the snapshot, using the old one if it isn't referenced.
+                        currentSnapshot = _owner.Snapshot(_snapshotRefCount == 0 ? currentSnapshot : null);
+                        _snapshotVersion = _owner._version;
+                        _snapshotRefCount = 0;
+                        _snapshot.SetTarget(currentSnapshot);
+                    }
+                    return currentSnapshot;
+                }
+            }
+
+            /// <summary>
+            /// Borrows a snapshot from a <see cref="ThreadView"/> and provides an enumerator.
+            /// Once <see cref="Dispose"/> is called the read lock is released.
+            /// </summary>
+            internal sealed class Enumerator : IEnumerator<TV>
+            {
+                private readonly IEnumerator<TV> _backing;
+                private readonly ThreadView _owner;
+                private bool _disposed;
+
+                internal Enumerator(ThreadView owner)
+                {
+                    _owner = owner;
+                    // Lock required since destructors run MT
+                    lock (_owner)
+                    {
+                        _owner._snapshotRefCount++;
+                        _backing = owner.GetSnapshot().GetEnumerator();
+                    }
+                    _disposed = false;
+                }
+
+                ~Enumerator()
+                {
+                    // Lock required since destructors run MT
+                    if (!_disposed && _owner != null)
+                        lock (_owner)
+                            Dispose();
+                }
+
+                public void Dispose()
+                {
+                    // safe deref so finalizer can clean up
+                    _backing?.Dispose();
+                    _owner._snapshotRefCount--;
+                    _disposed = true;
+                }
+
+                public bool MoveNext()
+                {
+                    if (_disposed)
+                        throw new ObjectDisposedException(nameof(Enumerator));
+                    return _backing.MoveNext();
+                }
+
+                public void Reset()
+                {
+                    if (_disposed)
+                        throw new ObjectDisposedException(nameof(Enumerator));
+                    _backing.Reset();
+                }
+
+                public TV Current
+                {
+                    get
+                    {
+                        if (_disposed)
+                            throw new ObjectDisposedException(nameof(Enumerator));
+                        return _backing.Current;
+                    }
+                }
+
+                object IEnumerator.Current => Current;
+            }
+        }
+
+        /// <inheritdoc/>
+        public IEnumerator<TV> GetEnumerator()
+        {
+            return new ThreadView.Enumerator(_threadViews.Value);
+        }
+
+        /// <inheritdoc/>
+        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+        #endregion
     }
 }

Torch/Collections/MtObservableDictionary.cs

@@ -0,0 +1,171 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.Specialized;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Torch.Utils;
+
+namespace Torch.Collections
+{
+    /// <summary>
+    /// Multithread safe observable dictionary
+    /// </summary>
+    /// <typeparam name="TK">Key type</typeparam>
+    /// <typeparam name="TV">Value type</typeparam>
+    public class MtObservableDictionary<TK, TV> : MtObservableCollection<IDictionary<TK, TV>, KeyValuePair<TK, TV>>, IDictionary<TK, TV>
+    {
+        /// <summary>
+        /// Creates an empty observable dictionary
+        /// </summary>
+        public MtObservableDictionary() : base(new Dictionary<TK, TV>())
+        {
+            Keys = new ProxyCollection<TK>(this, Backing.Keys, (x) => x.Key);
+            Values = new ProxyCollection<TV>(this, Backing.Values, (x) => x.Value);
+        }
+
+        protected override IDictionary<TK, TV> Snapshot(IDictionary<TK, TV> old)
+        {
+            if (old == null)
+                return new Dictionary<TK, TV>(Backing);
+            old.Clear();
+            foreach (KeyValuePair<TK, TV> k in Backing)
+                old.Add(k);
+            return old;
+        }
+
+        /// <inheritdoc/>
+        public bool ContainsKey(TK key)
+        {
+            using (Lock.ReadUsing())
+                return Backing.ContainsKey(key);
+        }
+
+        /// <inheritdoc/>
+        public void Add(TK key, TV value)
+        {
+            Add(new KeyValuePair<TK, TV>(key, value));
+        }
+
+        /// <inheritdoc/>
+        public bool Remove(TK key)
+        {
+            return TryGetValue(key, out TV result) && Remove(new KeyValuePair<TK, TV>(key, result));
+        }
+
+        /// <inheritdoc/>
+        public bool TryGetValue(TK key, out TV value)
+        {
+            using (Lock.ReadUsing())
+                return Backing.TryGetValue(key, out value);
+        }
+
+        /// <inheritdoc/>
+        public TV this[TK key]
+        {
+            get
+            {
+                using (Lock.ReadUsing())
+                    return Backing[key];
+            }
+            set
+            {
+                using (Lock.WriteUsing())
+                {
+                    var oldKv = new KeyValuePair<TK, TV>(key, Backing[key]);
+                    var newKv = new KeyValuePair<TK, TV>(key, value);
+                    Backing[key] = value;
+                    MarkSnapshotsDirty();
+                    OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace, newKv, oldKv));
+                }
+            }
+        }
+
+        /// <inheritdoc/>
+        public ICollection<TK> Keys { get; }
+
+        /// <inheritdoc/>
+        public ICollection<TV> Values { get; }
+
+        internal void RaiseFullReset()
+        {
+            OnPropertyChanged(nameof(Count));
+            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
+        }
+
+        private class ProxyCollection<TP> : ICollection<TP>
+        {
+            private readonly MtObservableDictionary<TK, TV> _owner;
+            private readonly ICollection<TP> _backing;
+            private readonly Func<KeyValuePair<TK, TV>, TP> _selector;
+
+            internal ProxyCollection(MtObservableDictionary<TK, TV> owner, ICollection<TP> backing, Func<KeyValuePair<TK, TV>, TP> selector)
+            {
+                _owner = owner;
+                _backing = backing;
+                _selector = selector;
+            }
+
+            /// <inheritdoc/>
+            public IEnumerator<TP> GetEnumerator() => new TransformEnumerator<KeyValuePair<TK, TV>, TP>(_owner.GetEnumerator(), _selector);
+
+            /// <inheritdoc/>
+            IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+            /// <inheritdoc/>
+            public void Add(TP item)
+            {
+                using (_owner.Lock.WriteUsing())
+                {
+                    _backing.Add(item);
+                    _owner.RaiseFullReset();
+                }
+            }
+
+            /// <inheritdoc/>
+            public void Clear()
+            {
+                _owner.Clear();
+            }
+
+            /// <inheritdoc/>
+            public bool Contains(TP item)
+            {
+                using (_owner.Lock.ReadUsing())
+                    return _backing.Contains(item);
+            }
+
+            /// <inheritdoc/>
+            public void CopyTo(TP[] array, int arrayIndex)
+            {
+                using (_owner.Lock.ReadUsing())
+                    _backing.CopyTo(array, arrayIndex);
+            }
+
+            /// <inheritdoc/>
+            public bool Remove(TP item)
+            {
+                using (_owner.Lock.WriteUsing())
+                {
+                    if (!_backing.Remove(item))
+                        return false;
+                    _owner.RaiseFullReset();
+                    return true;
+                }
+            }
+
+            /// <inheritdoc/>
+            public int Count
+            {
+                get
+                {
+                    using (_owner.Lock.ReadUsing())
+                        return _backing.Count;
+                }
+            }
+
+            public bool IsReadOnly => _backing.IsReadOnly;
+        }
+    }
+}

Torch/Collections/MtObservableList.cs

@@ -0,0 +1,128 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Specialized;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Torch.Utils;
+
+namespace Torch.Collections
+{
+    /// <summary>
+    /// Multithread safe, observable list
+    /// </summary>
+    /// <typeparam name="T">Value type</typeparam>
+    public class MtObservableList<T> : MtObservableCollection<IList<T>, T>, IList<T>
+    {
+        /// <summary>
+        /// Initializes a new instance of the MtObservableList class that is empty and has the default initial capacity.
+        /// </summary>
+        public MtObservableList() : base(new List<T>())
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the MtObservableList class that is empty and has the specified initial capacity.
+        /// </summary>
+        /// <param name="capacity"></param>
+        public MtObservableList(int capacity) : base(new List<T>(capacity))
+        {
+        }
+
+        protected override IList<T> Snapshot(IList<T> old)
+        {
+            if (old == null)
+            {
+                var list = new List<T>(Backing);
+                return list;
+            }
+            old.Clear();
+            if (old is List<T> tmp)
+                tmp.AddRange(Backing);
+            else
+                foreach (T k in Backing)
+                    old.Add(k);
+            return old;
+        }
+
+        /// <inheritdoc/>
+        public int IndexOf(T item)
+        {
+            using (Lock.ReadUsing())
+                return Backing.IndexOf(item);
+        }
+
+        /// <inheritdoc/>
+        public void Insert(int index, T item)
+        {
+            using(Lock.WriteUsing())
+            {
+                Backing.Insert(index, item);
+                MarkSnapshotsDirty();
+                OnPropertyChanged(nameof(Count));
+                OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item, index));
+            }
+        }
+
+        /// <inheritdoc/>
+        public void RemoveAt(int index)
+        {
+            using (Lock.WriteUsing())
+            {
+                T old = Backing[index];
+                Backing.RemoveAt(index);
+                MarkSnapshotsDirty();
+                OnPropertyChanged(nameof(Count));
+                OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, old, index));
+            }
+        }
+
+        /// <inheritdoc/>
+        public T this[int index]
+        {
+            get
+            {
+                using(Lock.ReadUsing())
+                    return Backing[index];
+            }
+            set
+            {
+                using(Lock.ReadUsing()) { 
+                    T old = Backing[index];
+                    Backing[index] = value;
+                    MarkSnapshotsDirty();
+                    OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace, value, old, index));
+                }
+            }
+        }
+
+        /// <inheritdoc/>
+        public void RemoveWhere(Func<T, bool> predicate)
+        {
+            for (int i = Count - 1; i >= 0; i--)
+                if (predicate(this[i]))
+                    RemoveAt(i);
+        }
+
+        /// <summary>
+        /// Sorts the list using the given selector and comparer./>
+        /// </summary>
+        public void Sort<TKey>(Func<T, TKey> selector, IComparer<TKey> comparer = null)
+        {
+            using (Lock.ReadUsing()) { 
+                comparer = comparer ?? Comparer<TKey>.Default;
+                if (Backing is List<T> lst)
+                    lst.Sort(new TransformComparer<T, TKey>(selector, comparer));
+                else
+                {
+                    List<T> sortedItems = Backing.OrderBy(selector, comparer).ToList();
+                    Backing.Clear();
+                    foreach (T v in sortedItems)
+                        Backing.Add(v);
+                }
+
+                OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
+            }
+        }
+    }
+}

Torch/Collections/ObservableDictionary.cs

@@ -1,151 +0,0 @@
-using System;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.Specialized;
-using System.ComponentModel;
-using System.Linq;
-using System.Runtime.CompilerServices;
-using System.Text;
-using System.Threading.Tasks;
-using System.Windows.Threading;
-
-namespace Torch.Collections
-{
-    [Serializable]
-    public class ObservableDictionary<TKey, TValue> : ViewModel, IDictionary<TKey, TValue>
-    {
-        private IDictionary<TKey, TValue> _internalDict;
-
-        public ObservableDictionary()
-        {
-            _internalDict = new Dictionary<TKey, TValue>();
-        }
-
-        public ObservableDictionary(IDictionary<TKey, TValue> dictionary)
-        {
-            _internalDict = new Dictionary<TKey, TValue>(dictionary);
-        }
-
-        /// <summary>
-        /// Create a <see cref="ObservableDictionary{TKey,TValue}"/> using the given dictionary by reference. The original dictionary should not be used after calling this.
-        /// </summary>
-        public static ObservableDictionary<TKey, TValue> ByReference(IDictionary<TKey, TValue> dictionary)
-        {
-            return new ObservableDictionary<TKey, TValue>
-            {
-                _internalDict = dictionary
-            };
-        }
-
-        /// <inheritdoc />
-        public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
-        {
-            return _internalDict.GetEnumerator();
-        }
-
-        /// <inheritdoc />
-        IEnumerator IEnumerable.GetEnumerator()
-        {
-            return ((IEnumerable)_internalDict).GetEnumerator();
-        }
-
-        /// <inheritdoc />
-        public void Add(KeyValuePair<TKey, TValue> item)
-        {
-            Add(item.Key, item.Value);
-        }
-
-        /// <inheritdoc />
-        public bool Remove(KeyValuePair<TKey, TValue> item)
-        {
-            return Remove(item.Key);
-        }
-
-        /// <inheritdoc />
-        public void Clear()
-        {
-            _internalDict.Clear();
-            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
-            OnPropertyChanged(nameof(Count));
-        }
-
-        /// <inheritdoc />
-        public bool Contains(KeyValuePair<TKey, TValue> item)
-        {
-            return _internalDict.Contains(item);
-        }
-
-        /// <inheritdoc />
-        public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
-        {
-            foreach (var kv in _internalDict)
-            {
-                array[arrayIndex] = kv;
-                arrayIndex++;
-            }
-        }
-
-        /// <inheritdoc />
-        public int Count => _internalDict.Count;
-
-        /// <inheritdoc />
-        public bool IsReadOnly => false;
-
-        /// <inheritdoc />
-        public bool ContainsKey(TKey key)
-        {
-            return _internalDict.ContainsKey(key);
-        }
-
-        /// <inheritdoc />
-        public void Add(TKey key, TValue value)
-        {
-            _internalDict.Add(key, value);
-            var kv = new KeyValuePair<TKey, TValue>(key, value);
-            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, kv));
-            OnPropertyChanged(nameof(Count));
-        }
-
-        /// <inheritdoc />
-        public bool Remove(TKey key)
-        {
-            if (!_internalDict.ContainsKey(key))
-                return false;
-
-            var kv = new KeyValuePair<TKey, TValue>(key, this[key]);
-            if (!_internalDict.Remove(key))
-                return false;
-
-            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, kv));
-            OnPropertyChanged(nameof(Count));
-            return true;
-        }
-
-        /// <inheritdoc />
-        public bool TryGetValue(TKey key, out TValue value)
-        {
-            return _internalDict.TryGetValue(key, out value);
-        }
-
-        /// <inheritdoc />
-        public TValue this[TKey key]
-        {
-            get => _internalDict[key];
-            set
-            {
-                var oldKv = new KeyValuePair<TKey, TValue>(key, _internalDict[key]);
-                var newKv = new KeyValuePair<TKey, TValue>(key, value);
-                _internalDict[key] = value;
-                OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace, newKv, oldKv));
-            }
-
-
-        }
-
-        /// <inheritdoc />
-        public ICollection<TKey> Keys => _internalDict.Keys;
-
-        /// <inheritdoc />
-        public ICollection<TValue> Values => _internalDict.Values;
-    }
-}

Torch/Collections/ObservableList.cs

@@ -1,155 +0,0 @@
-using System;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.Specialized;
-using System.ComponentModel;
-using System.Linq;
-using System.Runtime.CompilerServices;
-using System.Windows.Threading;
-
-namespace Torch
-{
-    /// <summary>
-    /// An observable version of <see cref="List{T}"/>.
-    /// </summary>
-    public class ObservableList<T> : ViewModel, IList<T>
-    {
-        private List<T> _internalList = new List<T>();
-
-        /// <inheritdoc />
-        public void Clear()
-        {
-            _internalList.Clear();
-            OnPropertyChanged(nameof(Count));
-            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
-        }
-
-        /// <inheritdoc />
-        public bool Contains(T item)
-        {
-            return _internalList.Contains(item);
-        }
-
-        /// <inheritdoc />
-        public void CopyTo(T[] array, int arrayIndex)
-        {
-            _internalList.CopyTo(array, arrayIndex);
-        }
-
-        /// <inheritdoc />
-        public bool Remove(T item)
-        {
-            var oldIndex = _internalList.IndexOf(item);
-            if (!_internalList.Remove(item))
-                return false;
-
-            OnPropertyChanged(nameof(Count));
-            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, item, oldIndex));
-            return true;
-        }
-
-        /// <inheritdoc />
-        public int Count => _internalList.Count;
-
-        /// <inheritdoc />
-        public bool IsReadOnly => false;
-
-        /// <inheritdoc />
-        public void Add(T item)
-        {
-            _internalList.Add(item);
-            OnPropertyChanged(nameof(Count));
-            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item, Count - 1));
-        }
-
-        /// <inheritdoc />
-        public int IndexOf(T item) => _internalList.IndexOf(item);
-
-        /// <inheritdoc />
-        public void Insert(int index, T item)
-        {
-            _internalList.Insert(index, item);
-            OnPropertyChanged(nameof(Count));
-            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item, index));
-        }
-
-        /// <summary>
-        /// Inserts an item in order based on the provided selector and comparer. This will only work properly on a pre-sorted list.
-        /// </summary>
-        public void Insert<TKey>(T item, Func<T, TKey> selector, IComparer<TKey> comparer = null)
-        {
-            comparer = comparer ?? Comparer<TKey>.Default;
-            var key1 = selector(item);
-            for (var i = 0; i < _internalList.Count; i++)
-            {
-                var key2 = selector(_internalList[i]);
-                if (comparer.Compare(key1, key2) < 1)
-                {
-                    Insert(i, item);
-                    return;
-                }
-            }
-
-            Add(item);
-        }
-
-        /// <inheritdoc />
-        public void RemoveAt(int index)
-        {
-            var old = this[index];
-            _internalList.RemoveAt(index);
-            OnPropertyChanged(nameof(Count));
-            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, old, index));
-        }
-
-        public T this[int index]
-        {
-            get => _internalList[index];
-            set
-            {
-                var old = _internalList[index];
-                if (old.Equals(value))
-                    return;
-
-                _internalList[index] = value;
-                OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace, value, old, index));
-            }
-        }
-
-        /// <summary>
-        /// Sorts the list using the given selector and comparer./>
-        /// </summary>
-        public void Sort<TKey>(Func<T, TKey> selector, IComparer<TKey> comparer = null)
-        {
-            comparer = comparer ?? Comparer<TKey>.Default;
-            var sortedItems = _internalList.OrderBy(selector, comparer).ToList();
-
-            _internalList = sortedItems;
-            OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
-        }
-
-        /// <summary>
-        /// Removes all items that satisfy the given condition.
-        /// </summary>
-        public void RemoveWhere(Func<T, bool> condition)
-        {
-            for (var i = Count - 1; i > 0; i--)
-            {
-                if (condition?.Invoke(this[i]) ?? false)
-                    RemoveAt(i);
-            }
-        }
-
-        /// <inheritdoc />
-        public IEnumerator<T> GetEnumerator()
-        {
-            return _internalList.GetEnumerator();
-        }
-
-        /// <inheritdoc />
-        IEnumerator IEnumerable.GetEnumerator()
-        {
-            return ((IEnumerable)_internalList).GetEnumerator();
-        }
-    }
-}

Torch/Collections/TransformComparer.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Torch.Collections
+{
+    /// <summary>
+    /// Comparer that uses a delegate to select the key to compare on.
+    /// </summary>
+    /// <typeparam name="TIn">Input to this comparer</typeparam>
+    /// <typeparam name="TCompare">Type of comparison key</typeparam>
+    public class TransformComparer<TIn, TCompare> : IComparer<TIn>
+    {
+        private readonly IComparer<TCompare> _comparer;
+        private readonly Func<TIn, TCompare> _selector;
+
+        /// <summary>
+        /// Creates a new transforming comparer that uses the given key selector, and the given key comparer.
+        /// </summary>
+        /// <param name="transform">Key selector</param>
+        /// <param name="comparer">Key comparer</param>
+        public TransformComparer(Func<TIn, TCompare> transform, IComparer<TCompare> comparer = null)
+        {
+            _selector = transform;
+            _comparer = comparer ?? Comparer<TCompare>.Default;
+        }
+
+        /// <inheritdoc/>
+        public int Compare(TIn x, TIn y)
+        {
+            return _comparer.Compare(_selector(x), _selector(y));
+        }
+    }
+}

Torch/Collections/TransformEnumerator.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Torch.Collections
+{
+    /// <summary>
+    /// Enumerator that transforms from one enumeration into another.
+    /// </summary>
+    /// <typeparam name="TIn">Input type</typeparam>
+    /// <typeparam name="TOut">Output type</typeparam>
+    public class TransformEnumerator<TIn,TOut> : IEnumerator<TOut>
+    {
+        private readonly IEnumerator<TIn> _input;
+        private readonly Func<TIn, TOut> _transform;
+
+        /// <summary>
+        /// Creates a new transform enumerator with the given transform function
+        /// </summary>
+        /// <param name="input">Input to proxy enumerator</param>
+        /// <param name="transform">Transform function</param>
+        public TransformEnumerator(IEnumerator<TIn> input, Func<TIn, TOut> transform)
+        {
+            _input = input;
+            _transform = transform;
+        }
+
+        /// <inheritdoc/>
+        public void Dispose()
+        {
+            _input.Dispose();
+        }
+
+        /// <inheritdoc/>
+        public bool MoveNext()
+        {
+            return _input.MoveNext();
+        }
+
+        /// <inheritdoc/>
+        public void Reset()
+        {
+            _input.Reset();
+        }
+
+        /// <inheritdoc/>
+        public TOut Current => _transform(_input.Current);
+
+        /// <inheritdoc/>
+        object IEnumerator.Current => Current;
+    }
+}

Torch/Managers/KeenLogPatch.cs

@@ -14,7 +14,7 @@ using VRage.Utils;
 namespace Torch.Managers
 {
     [PatchShim]
-    internal class KeenLogManager
+    internal static class KeenLogPatch
     {
         private static readonly Logger _log = LogManager.GetLogger("Keen");
 
@@ -63,7 +63,7 @@ namespace Torch.Managers
 
         private static MethodInfo Method(string name)
         {
-            return typeof(KeenLogManager).GetMethod(name, BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.Public);
+            return typeof(KeenLogPatch).GetMethod(name, BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.Public);
         }
 
         [ReflectedMethod(Name = "GetThreadId")]

Torch/Managers/MultiplayerManagerBase.cs

@@ -48,7 +48,7 @@ namespace Torch.Managers
         /// <inheritdoc />
         public event Action<IPlayer> PlayerLeft;
 
-        public ObservableDictionary<ulong, PlayerViewModel> Players { get; } = new ObservableDictionary<ulong, PlayerViewModel>();
+        public MtObservableDictionary<ulong, PlayerViewModel> Players { get; } = new MtObservableDictionary<ulong, PlayerViewModel>();
 
 #pragma warning disable 649
         [ReflectedGetter(Name = "m_players")]

Torch/Plugins/PluginManager.cs

@@ -27,7 +27,7 @@ namespace Torch.Managers
         private static Logger _log = LogManager.GetLogger(nameof(PluginManager));
         private const string MANIFEST_NAME = "manifest.xml";
         public readonly string PluginDir = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Plugins");
-        private readonly ObservableDictionary<Guid, ITorchPlugin> _plugins = new ObservableDictionary<Guid, ITorchPlugin>();
+        private readonly MtObservableDictionary<Guid, ITorchPlugin> _plugins = new MtObservableDictionary<Guid, ITorchPlugin>();
 #pragma warning disable 649
         [Dependency]
         private ITorchSessionManager _sessionManager;

Torch/Torch.csproj

@@ -154,7 +154,11 @@
     <Compile Include="..\Versioning\AssemblyVersion.cs">
       <Link>Properties\AssemblyVersion.cs</Link>
     </Compile>
-    <Compile Include="Collections\ObservableList.cs" />
+    <Compile Include="Collections\MtObservableCollection.cs" />
+    <Compile Include="Collections\MtObservableDictionary.cs" />
+    <Compile Include="Collections\MtObservableList.cs" />
+    <Compile Include="Collections\TransformComparer.cs" />
+    <Compile Include="Collections\TransformEnumerator.cs" />
     <Compile Include="Event\EventShimAttribute.cs" />
     <Compile Include="Managers\ChatManager\ChatManagerClient.cs" />
     <Compile Include="Managers\ChatManager\ChatManagerServer.cs" />
@@ -164,7 +168,7 @@
     <Compile Include="Event\EventList.cs" />
     <Compile Include="Event\EventManager.cs" />
     <Compile Include="Event\IEventList.cs" />
-    <Compile Include="Managers\KeenLogManager.cs" />
+    <Compile Include="Managers\KeenLogPatch.cs" />
     <Compile Include="Managers\PatchManager\AssemblyMemory.cs" />
     <Compile Include="Managers\PatchManager\DecoratedMethod.cs" />
     <Compile Include="Managers\PatchManager\EmitExtensions.cs" />
@@ -190,7 +194,6 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="SaveGameStatus.cs" />
     <Compile Include="Collections\KeyTree.cs" />
-    <Compile Include="Collections\ObservableDictionary.cs" />
     <Compile Include="Collections\RollingAverage.cs" />
     <Compile Include="CommandLine.cs" />
     <Compile Include="Commands\CategoryAttribute.cs" />
@@ -215,6 +218,7 @@
     <Compile Include="Utils\Reflection.cs" />
     <Compile Include="Managers\ScriptingManager.cs" />
     <Compile Include="Utils\StringUtils.cs" />
+    <Compile Include="Utils\SynchronizationExtensions.cs" />
     <Compile Include="Utils\TorchAssemblyResolver.cs" />
     <Compile Include="Utils\ReflectedManager.cs" />
     <Compile Include="Session\TorchSessionManager.cs" />
@@ -224,7 +228,6 @@
     <Compile Include="Session\TorchSession.cs" />
     <Compile Include="Utils\TorchLauncher.cs" />
     <Compile Include="ViewModels\ModViewModel.cs" />
-    <Compile Include="Collections\MTObservableCollection.cs" />
     <Compile Include="Extensions\MyPlayerCollectionExtensions.cs" />
     <Compile Include="SteamHelper.cs" />
     <Compile Include="Extensions\StringExtensions.cs" />

Torch/Utils/SynchronizationExtensions.cs

@@ -0,0 +1,96 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Torch.Utils
+{
+    /// <summary>
+    /// Extension functions related to synchronization
+    /// </summary>
+    public static class SynchronizationExtensions
+    {
+
+        /// <summary>
+        /// Acquires a RAII view of the lock in read mode.
+        /// </summary>
+        /// <param name="lck">Lock</param>
+        /// <returns>RAII token</returns>
+        public static IDisposable ReadUsing(this ReaderWriterLockSlim lck)
+        {
+            return new ReaderWriterLockSlimReadToken(lck);
+        }
+
+        /// <summary>
+        /// Acquires a RAII view of the lock in upgradable read mode.
+        /// </summary>
+        /// <param name="lck">Lock</param>
+        /// <returns>RAII token</returns>
+        public static IDisposable UpgradableReadUsing(this ReaderWriterLockSlim lck)
+        {
+            return new ReaderWriterLockSlimUpgradableToken(lck);
+        }
+
+        /// <summary>
+        /// Acquires a RAII view of the lock in write mode.
+        /// </summary>
+        /// <param name="lck">Lock</param>
+        /// <returns>RAII token</returns>
+        public static IDisposable WriteUsing(this ReaderWriterLockSlim lck)
+        {
+            return new ReaderWriterLockSlimWriteToken(lck);
+        }
+
+        #region Support Structs
+        private struct ReaderWriterLockSlimUpgradableToken : IDisposable
+        {
+            private ReaderWriterLockSlim _lock;
+
+            public ReaderWriterLockSlimUpgradableToken(ReaderWriterLockSlim lc)
+            {
+                _lock = lc;
+                lc.EnterUpgradeableReadLock();
+            }
+
+            public void Dispose()
+            {
+                _lock.ExitUpgradeableReadLock();
+            }
+        }
+
+        private struct ReaderWriterLockSlimWriteToken : IDisposable
+        {
+            private ReaderWriterLockSlim _lock;
+
+            public ReaderWriterLockSlimWriteToken(ReaderWriterLockSlim lc)
+            {
+                _lock = lc;
+                lc.EnterWriteLock();
+            }
+
+            public void Dispose()
+            {
+                _lock.ExitWriteLock();
+            }
+        }
+
+        private struct ReaderWriterLockSlimReadToken : IDisposable
+        {
+            private ReaderWriterLockSlim _lock;
+
+            public ReaderWriterLockSlimReadToken(ReaderWriterLockSlim lc)
+            {
+                _lock = lc;
+                lc.EnterReadLock();
+            }
+
+            public void Dispose()
+            {
+                _lock.ExitReadLock();
+            }
+        }
+        #endregion
+    }
+}